Die tool



Oct. 31, 1944. J. A BROERSMA DIE TOOL 2 Sheets-Sheet l Filed Jan. 10, 1944 INVENTOR. baco l9- Broersma Nnr-rgzy Oct. 31, 1944. J A. BRQERSMA 2,361,595

DIE TOOL Filed Jan. 10, 1944 2 Sheets-Sheet 2 acob A. Bmarsma w E rm:

l lg 1 Patented Oct. 31, 1944 UNITED STATES eATENT OFFICE 4 Claims.

My present invention relates to improvements in die tools, and particularly to die tools employed in connection with punch presses and the like, for severing metal tubes into portions, and the objects of improvement are: first, to provide a die tool that will sever thin walled metal tubing cleanly; second, to provide a die tool that will sever thin walled metal tubing without leaving fins or burrs at the inner side of the tube wall; third, to provide a die tool that will not squash thin walled metal tubing when being cut transversely.

These named objects and such other objects as may appear from a perusal of the following description taken with reference to the accompanying drawings, are attained by the structure disclosed in the drawings, in which:

Figure 1 is a top plan view of the die portion of the die tool with the die block sliding bar shown in cross-section.

Figure 2 is a front elevation of the die portion of the die tool with a section of metal tubing held thereby in readiness to be severed.

Figure 3 is a side elevation of the die tool in which the cutting punch together with the holder therefor and guide bar is in raised position.

Figure 4 is a side elevation of the die tool as when in the act of severing a thin walled metal tube; and with the cutter or punch and guide bar broken oif adjacent the top of the die blocks.

Throughout the several views of the accompanying drawings similar numeral characters refor to similar parts and portions of my die tool, and referring thereto:

Numeral l designates the platen of a punch press on which is mounted my die tool consisting of base member 2 having secured thereto on its top, die block portion 3 having depression 4 of less than semicircle form into which is held the metal tube to be severed and having a radius greater than the radius of the outer periphery of the tube; also secured to the top of the base member 2 is slideway gibs 5 in transversely spaced apart relation to each other, and between which is slidable die block portion 6 engaged by. rollers and 8 carried by die block sliding bar 9 secured to and extending downward from punch carrying plate It secured to head plate ll clamped to the ram l2 of the punch press.

The punch plate It) has secured to it, downwardly extending tube severing cutter or punch l3 having at its tube severing end concave cutting edges I4, I5, and tube piercing point i6. Secured to the base member 2 and extending upward therefrom is post I! having at its upper end roller I8 engaging the die block sliding bar 9 carrying rollers l and 8 engaging the die block portion 6 having inclined cam surface 6' for starting the block portion to slide when engaged by roller 1 of the die block sliding bar 9. The die block portion 6 has in its side adjacent the depression 4 of the die'block portion 3, depression I9 similar to the depression 4 of the die block portion 3, the said depression l9 being in opposed relation to said depression 4 and like die block 3 has a greater radius than the radius of the outer periphery of the tube being severed.

Numeral 2!! designates the thin walled metal tube held in the depressions 4 and I9 and squashed out of true cylindrical form as shown in Figure 4 during the severing operation.

Numeral 2| refers to the slot into which the punch l3 enters for severing the metal tube; the said slot having at each of its vertical narrow sides, chip clearance space 22 extending downward and underneath the cutting edge of semicircular rings 4' and I9. Numerals 23 and 24 refer to hardened steel die blocks set into the die block portion 3 and numerals 25 and 26 refer to similar hardened steel die blocks set into die block portion 6. The purpose of the hardened steel die blocks 23, 24, 25 and 26 being to prolong the cutting edge of the die tool and permit renewal of the die blocks 23, 24, 25 and 26 without the necessity of renewing the die block portions 3 and 3 which are expensive to produce.

In employing my die tool in the operation of severing thin wall tubing, the base member 2 is secured on the platen of a suitable punch press and the punch carrying plate It] is secured to the head plate ll having an upwardly extending trunnion which is clamped to the reciprocal ram of the press, the press is then started in motion, which motion causes the ram of the press to reciprocate vertically and in so doing, to cause the punch or cutter l3 to pass downward in the slot 2| and upward therefrom, and as the punch or cutter clears the top of the die blocks, the die block portion 6 moves slightly away from the die block portion 3, at which timethe thin walled tube is slid through the opening caused by the depressions 4 and I9, and as the ram travels downward the roller 1 carried by the die block sliding bar 9, first engages the cam surface 6 of the die block portion 6, and forces the die block portion 6 toward the die block portion 3, and as the opening caused by the depressions 4 and l9' is narrower horizontally than vertically, the tube therein is squashed out of cylindrical form and forced against the upper sid of the said oval opening formed by the depressions 4 and I9 thereby causing the tube to assume an arch its upper and lower arcs of less radius than the radius of the tube when in its cylindrical form, thereby permitting the cutting punch or cutter to first pierce the Wall of the tube by the point l6 and further shear the tube by the concave cutting edges M and I5 and thereby severing the tube cleanly without producing burrs or fins.

Having described my present invention, the rights of which I desire to secure by Letters Patent are:

1. In a die tool; comprising for operation on a metal tube to be severed, a base member and a punch plate, a pair of slideway gibs secured to the top of the base member in spaced apart relation to each other, a die block having a concave depression of less than half of a circle and having a greater radius than the radius of the outer periphery of the tube and secured to the top of the said base member and having its depression facing the said slideway gibs, a die block slidable between the slideway gibs and having a concave depression of less than half of a circle and having a radius greater than the radius of the outer periphery of the tube facing the depression in the first named die block, a hardened steel member carried by each of said die blocks and having a slot for receiving a tube cutter punch, a punch plate carried by the ram of a punch press and having a bar with a pair of rollers mounted thereon for engaging one of the slidable die blocks for moving the said die block to engage and deform a metal tube to be severed, and a cutter punch carried by the punch plate for severing the metal tube within the slot of the said die blocks.

2. In a die tool: for operation upon a tube to be severed a base member and a punch plate, a pair of slideway gibs secured to the top of the base member in spaced apart relation to each 7 other, a die block having a concave depression of greater radius than the greater radius of the tube to be severed adjacent its top secured to the top of the said base member and having its depression facing the said slideway gibs, a die block slidable between the slideway gibs and having a concave depression of greater radius than the greater radius of the tube adjacent its top and facing the depression in the first named die block, a hardened steel replaceable member carried by each of said die blocks and having a slot for receiving a tube cutter punch, and guiding a punch plate carried by and sliding on the ram of a punch press and having a bar with a pair of rollers mounted thereon for engaging the slidable die blocks.

3. In a die tool adapted to sever metal tubing, the combination with a cutter for severing the tube of a pair of die blocks in spaced apart relation to each other and each having a part circle depression of less than one-half the circumference of the tube to be severed and a greater radius than the greater radius of the tube, and having a pair of hardened steel members closely fitting the cutter for guiding the cutter.

4. In a die tool adapted to sever metal tubing, the combination with a cutter for severing the tube of a pair of die blocks in spaced apart relation to ach other and each having a part circle depression of less than one-half the circumference of the tube to be severed and of greater radius than the greater radius of the tube.

JACOB A. BROERSMA. 

